21382944 has 48 divisors (see below), whose sum is σ = 61236000. Its totient is φ = 6479360.

The previous prime is 21382943. The next prime is 21382967. The reversal of 21382944 is 44928312.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21382943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9069 + ... + 11180.

It is an arithmetic number, because the mean of its divisors is an integer number (1275750).

Almost surely, 2^21382944 is an apocalyptic number.

21382944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21382944 is an abundant number, since it is smaller than the sum of its proper divisors (39853056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21382944 is a wasteful number, since it uses less digits than its factorization.

21382944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20273 (or 20265 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21382944 is about 4624.1695470646. The cubic root of 21382944 is about 277.5593315227.

The spelling of 21382944 in words is "twenty-one million, three hundred eighty-two thousand, nine hundred forty-four".